Hi Fadi this is an article I found from 2012 on World a Potash Developments and it shows all the major players projects with the associated grades the range from around 7% k2O to high end 21%K2O. The last I read was Satimola had a confirmed JORC of 6billion Tonnes at 15.5% k2O(see below )
September 4, 2013: Approval granted from the Ministry of Industry and New Technologies of the Republic of Kazakhstan (MINT) to proceed with the acquisition of a 100% shareholding in Satimola Limited. The Satimola reserve is one of the world’s largest undeveloped potash resources with a JORC compliant resources of over 6.0 billion tonnes grading 15.5% K2O (10% K2O cut- off grade).
i don't know how to hyperlink this article from iPad